Ship fuel oil pretreatment desulfurization system using pretreatment desulfurization agent

ABSTRACT

Proposed is a pretreatment desulfurization system including a desulfurization agent storage tank for storing a liquid-phase pretreatment desulfurization agent and a metering pump for supplying the liquid-phase pretreatment desulfurization agent from the desulfurization agent storage tank to a fuel supply line through which marine fuel oil is supplied to a marine engine in a predetermined ratio. Since a fluid mixture composed of the marine fuel oil and the pretreatment desulfurization agent is supplied to the marine engine, sulfur oxides are adsorbed and removed during combustion of the fluid mixture.

TECHNICAL FIELD

The present invention relates to a marine fuel oil pretreatmentdesulfurization system using a pretreatment desulfurization agent. Moreparticularly, the present invention relates to a marine fuel oilpretreatment desulfurization system using a pretreatment desulfurizationagent having a pretreatment desulfurization function, the system beingcapable of absorbing and reducing sulfur oxides (SO_(X)) when marinefuel oil such as bunker C-oil commonly used as a fuel for a marineengine is burned, thereby reducing sulfur oxides (SO_(X)) emissionsduring combustion of the marine fuel oil.

BACKGROUND ART

Sulfur oxides (SO_(X)) and nitrogen oxides (NO_(x)) are pointed out aspollutants that cause air pollution. In particular, sulfur oxides arecontained in industrial flue gas emitted from the combustion of fossilfuels containing sulfur, and the sulfur oxides cause variousenvironmental pollution problems such as acid rain.

Desulfurization technology for removing sulfur oxides from industrialflue gas has been continuously studied, and a flue gas desulfurizationmethod of treating flue gas after combustion of fossil fuels has beengenerally used in factories or power plants.

The flue gas desulfurization method refers to a method of desulfurizingthe flue gas after burning a fossil fuels containing sulfur, and theflue gas desulfurization methods are categorized into wet treatment anddry treatment. A wet treatment method removes sulfur oxides by washingflue gas with ammonia water, sodium hydroxide solution, lime milk, etc.while a dry treatment method removes sulfur oxides by brining particlesor powders of activated carbon or carbonates into contact with flue gasto adsorb or react with sulfur dioxide.

In particular, the sulfur oxide content of heavy fuel oil (MGO, MDO, orDDO) such as bunker C-oil used in marine engines is 1,000 to 3,000 timeshigher than that of automobile fuel. The amount of sulfur oxides emittedby ships around the world is 130 times higher than that by automobilesand thus is known as the main cause of environmental pollution.

For this reason, conventionally, flue gas desulfurization, which is apost-treatment process performed after combustion of fuel, is used. Thefuel gas desulfurization uses a marine wet desulfurization system toremove sulfur oxides emitted from marine engines. In the wetdesulfurization system, a pump is used to supply washing water (NaOH),which is usually, to a scrubber through a cooler, and the washing watercomes into contact with flue gas in the scrubber. In this case, sulfuroxides are removed through a pose-treatment process.

In this case, to maintain or boost the sulfur oxide removal capabilityof the wet desulfurization system at or to a predetermined level, the pHof the washing water is monitored, and the supply amount of the washingwater is automatically controlled. To recycle the washing water, theused washing water is purified, and a huge amount of sludge is generatedduring the purification of the washing water. The sludge is usuallycollected and stored in a sludge tank during sailing, and the sludge istreated after the ship is anchored.

As described above, the conventional post-treatment wet desulfurizationtechnology requires a lot of manpower and cost due to the complicatedwashing water purification process, and it is necessary to separatelyconstruct a separate complex desulfurization facility. Therefore, it isdifficult to apply such a conventional desulfurization system tocurrently operating ships. That is, there is a problem that it is noteasy and practical to use the conventional desulfurization system in anexisting ship in terms of space and cost.

Therefore, in order to dramatically reduce the environmental pollutioncaused by the combustion of marine fuel oil and by the emission ofsulfur oxides, research on an effective pretreatment desulfurizationsystem that can significantly reduce the emission of sulfur oxides, caneasily remove sulfur oxides, and can be easily applied to an existingship is urgently needed.

DISCLOSURE Technical Problem

The present invention has been made to solve the problems occurring inthe related art, and an objective of the present invention is to providea pretreatment desulfurization system for marine fuel oil, the systembeing capable of preventing sulfur oxides from being discharged into theair during the combustion of high sulfur marine fuel oil, being able tobe simply and easily applied to an existing ship, and having a highdesulfurization effect.

Technical Solution

In order to solve the technical problem, according to one embodiment ofthe present invention, there is provided a pretreatment desulfurizationsystem including: a desulfurization agent storage tank for storing aliquid-phase pretreatment desulfurization agent; and a metering pump forsupplying the liquid-phase pretreatment desulfurization agent from thedesulfurization agent storage tank to a fuel supply line through whichmarine fuel oil is supplied to a marine engine in a predetermined ratio.Since a fluid mixture composed of the marine fuel oil and thepretreatment desulfurization agent is supplied to the marine engine,sulfur oxides are adsorbed and removed during combustion of the fluidmixture.

In addition, according to one embodiment, the pretreatmentdesulfurization agent may include: (a) at least one oxide selected fromthe group consisting of SiO₂, Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O,K₂O, and P₂O₃; (b) at least one metal selected from the group consistingof Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; and (c) at least oneliquid composition selected from the group consisting of sodiumtetraborate (Na₂B₄O₇·10H₂O), sodium hydroxide (NaOH), sodium silicate(Na₂SiO₃), and hydrogen peroxide (H₂O₂).

In addition, according to one embodiment, the oxide may include 15 to 90parts by weight of SiO₂, 15 to 100 parts by weight of Al₂O₃, 10 to 50parts by weight of Fe₂O₃, 5 to 15 parts by weight of TiO₂, 20 to 150parts by weight of MgO, 10 to 20 parts by weight of MnO, 20 to 200 partsby weight of CaO, 15 to 45 parts by weight of Na₂O, 20 to 50 parts byweight of K₂O, and 5 to 20 parts by weight of P₂O₃, and the metal mayinclude 0.0035 to 0.009 parts by weight of Li, 0.005 to 0.01 parts byweight of Cr, 0.001 to 0.005 parts by weight of Co, 0.006 to 0.015 partsby weight of Ni, 0.018 to 0.03 parts by weight of Cu, 0.035 to 0.05parts by weight of Zn, 0.04 to 0.08 parts by weight of Ga, 0.02 to 0.05parts by weight of Sr, 0.002 to 0.01 parts by weight of Cd, and 0.003 to0.005 parts by weight of Pb.

In addition, according to one embodiment, the oxide and metal may have aparticle size of 1 to 2 μm and a specific gravity of 2.5 to 3.0.

In addition, according to one embodiment, the sodium tetraborate(Na₂B₄O₇·10H₂O) may be contained in an amount of 20 to 130 parts byweight, the sodium hydroxide (NaOH) may be contained in an amount of 15to 120 parts by weight, the sodium silicate (Na₂SiO₃) may be containedin an amount of 50 to 250 parts by weight, and the hydrogen peroxide(H₂O₂) may be contained in an amount of 10 to 50 parts by weight.

In addition, according to one embodiment, the pretreatmentdesulfurization agent may be configured such that the oxide, the metal,and the liquid composition form a metal chelate compound.

In addition, according to one embodiment, the pretreatmentdesulfurization agent may have a sulfur oxide (SO_(X)) adsorption effectthat is activated at a temperature in a range of 400° C. to 1200° C.

In addition, according to one embodiment, the pretreatmentdesulfurization agent may be mixed with the marine fuel oil in a ratioof 0.1 to 10 parts by weight to 100 parts by weight.

In addition, according to one embodiment, the pretreatmentdesulfurization agent may be mixed with the marine fuel oil in a ratioof 6 parts by weight to 100 parts by weight.

In addition, according to one embodiment, the fuel supply line may beequipped with a line mixer, and the metering pump may introduce thepretreatment desulfurization agent into the marine fuel oil in a statein which the metering pump is connected to the line mixer.

In addition, according to one embodiment, a flow meter, a check valve,and a pressure gauge may be further included between the line mixer andthe metering pump.

In addition, according to one embodiment, the marine fuel oil may be anyheavy oil among heavy oils including bunker-A oil, bunker-B oil, andbunker-C oil, or any light oil among light oils including MGO, MDO, andDDO.

Advantageous Effects

According to the present invention, the marine fuel oil pretreatmentdesulfurization system using the pretreatment desulfurization agent canprevent a large amount of sulfur oxides from being emitted into the airduring combustion of high sulfur marine fuel oil, thereby greatlycontributing to solving the problem of air pollution caused by sulfuroxides.

In addition, the pretreatment desulfurization system of the presentinvention is different from a conventional desulfurization system inwhich exhaust gas is desulfurized after the combustion of fuel. That is,the pretreatment desulfurization agent is mixed with marine fuel oilbefore the marine fuel oil is combusted, and the marine fuel oil and thepretreatment desulfurization agent are combusted together by a marineengine. It is easy and simple to apply the pretreatment desulfurizationsystem to an existing ship by connecting the predetermineddesulfurization system to a fuel supply system for an existing marineengine without requiring an additional desulfurization facility, and thepretreatment desulfurization system has a high desulfurization effect.

DESCRIPTION OF DRAWINGS

FIG. 1 is an exemplary view illustrating the construction of apretreatment desulfurization system according to the present invention;

FIG. 2 is a partially enlarged view of a region A of FIG. 1 ;

FIG. 3 is a view illustrating the result of analysis of a sulfur oxide(SO₂) concentration in the entire session of Experimental Example 1; and

FIG. 4 is a view illustrating the result of analysis of a sulfur oxide(SO₂) concentration in the entire session of Experimental Example 2.

BEST MODE

In the following description, the specific structural or functionaldescriptions for exemplary embodiments according to the concept of thepresent disclosure are merely for illustrative purposes. So, thoseskilled in the art will appreciate that various modifications andchanges to the exemplary embodiments are possible, without departingfrom the scope and spirit of the present disclosure. Therefore, thepresent disclosure is intended to cover not only the exemplaryembodiments but also various alternatives, modifications, equivalents,and other embodiments that may be included within the spirit and scopeof the embodiments as defined by the appended claims. Hereinafter,embodiments of the present invention will be described in detail inconjunction with the accompanying drawings.

The present invention uses a desulfurization catalyst (hereinafter,referred to as “pretreatment desulfurization agent”) including: (a) atleast one oxide selected from the group consisting of SiO₂, Al₂O₃,Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O, K₂O, and P₂O₃; (b) at least one metalselected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr,Cd, and Pb; and (c) at least one liquid composition selected from thegroup consisting of sodium tetraborate (Na₂B₄O₇·10 H₂O), sodiumhydroxide (NaOH), sodium silicate (Na₂SiO₃) and hydrogen peroxide(H₂O₂).

The pretreatment desulfurization agent according to the presentinvention preferably includes at least one oxide selected from the groupconsisting of SiO₂, Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O, K₂O, andP₂O₃. Preferably, the pretreatment desulfurization agent includes all ofthe oxides selected from the group consisting of SiO₂, Al₂O₃, Fe₂O₃,TiO₂, MgO, MnO, CaO, Na₂O, K₂O, and P₂O₃ as in one example describedbelow.

When including all of SiO₂, Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O,K₂O, and P₂O₃, the basic formula is K_(0.8-0.9) (Al, Fe, Mg)₂ (Si,Al)₄O₁₀ (OH)₂ which is a mineral commonly called illite. The illite hasa 2:1 structure in which one octahedral layer is bonded between twotetrahedral layers. The octahedral layer has a dioctahedral structure inwhich only 2 cation sites out of 3 cation sites in the bonding structureare filled with cations. Due to the lack of cations, the illite isoverall negatively charged (−). For this reason, sulfur oxides (SO_(X))can be adsorbed when the mixture of a combustible material and thedesulfurization catalyst is burned.

As the oxides, the pretreatment desulfurization agent may include 15 to90 parts by weight of SiO₂, 15 to 100 parts by weight of Al₂O₃, 10 to 50parts by weight of Fe₂O₃, 5 to 15 parts by weight of TiO₂, 20 to 150parts by weight of MgO, 10 to 20 parts by weight of MnO, and 20 to 200parts by weight of CaO, 15 to 45 parts by weight of Na₂O, 20 to 50 partsby weight of K₂O, and 5 to 20 parts by weight of P₂O₃.

In addition, the oxides may be mixed and pulverized into fine particleshaving a particle size of 1 to 2 μm by a pulverizer before beingprepared as the desulfurization catalyst. The oxides may have a specificgravity of 2.5 to 3.0 and may be in the form of powder that isstreak-colored or silvery white.

The pretreatment desulfurization agent according to the presentinvention may include one or more metals selected from the groupconsisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb. As in oneembodiment, all of the metals including Li, Cr, Co, Ni, Cu, Zn, Ga, Sr,Cd, and Pb are preferably included.

As the metals, the pretreatment desulfurization agent may include 0.0035to 0.009 parts by weight of Li, 0.005 to 0.01 parts by weight of Cr,0.001 to 0.005 parts by weight of Co, 0.006 to 0.015 parts by weight ofNi, 0.018 to 0.03 parts by weight of Cu, 0.035 to 0.05 parts by weightof Zn, 0.04 to 0.08 parts by weight of Ga, 0.02 to 0.05 parts by weightof Sr, 0.002 to 0.01 parts by weight of Cd, and 0.003 to 0.005 parts byweight of Pb.

In addition, the metals, like the oxides, may be mixed and pulverizedinto fine particles having a particle size of 1 to 2 μm by a pulverizer,the metals may have a specific gravity of 2.5 to 3.0, and the metals maybe in the form of powder that is streak-colored and silvery white.

The pretreatment desulfurization agent according to the presentinvention may include at least one liquid composition selected from thegroup consisting of sodium tetraborate (Na₂B₄O₇·10H₂O), sodium hydroxide(NaOH), sodium silicate (Na₂SiO₃) and hydrogen peroxide (H₂O₂)Preferably, as in one embodiment, all of the liquid compositionsincluding sodium tetraborate, sodium hydroxide, sodium silicate, andhydrogen peroxide may be contained.

The pretreatment desulfurization agent according to the presentinvention forms a metal chelate compound through coordination with themetals because the oxides and the liquid compositions are mixed andreacted to serve as a chelating agent.

In addition, the liquid composition may be adsorbed on ash generatedwhen a combustible material is combusted so that the liquid compositionmay react with sulfur oxides present in the ash, thereby removing thesulfur oxides. NaBO₂ is derived from the sodium tetraborate (Na₂B₄O₇),NaBH₄ is produced through hydrogenation, and the produced NaBH₄ reactswith oxygen and sulfur oxides to form sodium sulfate (Na₂SO₄). Thus, thesulfur oxides are removed. The reactions are represented by ReactionFormulas 1 and 2 below.

NaBH₄+O₃→Na₂O₂+H₂O+B  [Reaction Formula 1]

1)Na₂O₂+SO₃→Na₂SO_(4+O) 2)Na₂O₂+SO₂→Na₂SO₄ 3)Na₂O₂+SO→Na₂SO₃  [ReactionFormula 2]

In addition, as the liquid compositions, the sodium tetraborate, thesodium hydroxide, the sodium silicate, and the hydrogen peroxide may beincluded in amounts of 20 to 130 parts by weight, 15 to 120 parts byweight, 50 to 250 parts by weight, and 10 to 50 parts by weight,respectively in the pretreatment desulfurization agent.

When the pretreatment desulfurization agent according to the presentinvention is mixed with a combustible material and combusted together ata temperature in a range of 400° C. to 1200° C., the effect of adsorbingsulfur oxides can be activated. However, when the mixture is combustedin a temperature range of 600° C. to 900° C., high efficiency can beobtained.

Hereinafter, a method of preparing the pretreatment desulfurizationagent according to the present invention will be described.

The pretreatment desulfurization agent according to the presentinvention is prepared through a method including: (a) preparing an oxidepowder by mixing and finely pulverizing at least one oxide selected fromthe group consisting of SiO₂, Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O,K₂O, and P₂O₃; (b) preparing a metal powder by mixing and finelypulverizing at least one metal selected from the group consisting of Li,Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb; and (c) mixing the oxide mixtureprepared in (a) and the metal mixture prepared in (b) with at least oneliquid composition selected from the group consisting of sodiumtetraborate (Na₂B₄O₇·10 H₂O), sodium hydroxide (NaOH), sodium silicate(Na₂SiO₃), and hydrogen peroxide (H₂O₂)

In step (a), the oxide powder including at least one oxide selected fromthe group consisting of SiO₂, Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O,K₂O, and P₂O₃ is mixed and finely ground with a fine pulverizer.

In this step, the oxide power includes 15 to 90 parts by weight of SiO₂,15 to 100 parts by weight of Al₂O₃, 10 to 50 parts by weight of Fe₂O₃, 5to 15 parts by weight of TiO₂, 20 to 150 parts by weight of MgO, 10 to20 parts by weight of MnO, and 20 to 200 parts by weight of CaO, 15 to45 parts by weight of Na₂O, 20 to 50 parts by weight of K₂O, and 5 to 20parts by weight of P₂O₃.

In addition, the finely ground oxide powder may be ground repeatedlyuntil the particle size of the powder falls within a range of 1 to 2 μm.

In step (b), the metal powder including at least one metal selected fromthe group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd and Pb ismixed and ground with a fine pulverizer.

The metal powder may include 0.0035 to 0.009 parts by weight of Li,0.005 to 0.01 parts by weight of Cr, 0.001 to 0.005 parts by weight ofCo, 0.006 to 0.015 parts by weight of Ni, 0.018 to 0.03 parts by weightof Cu, 0.035 to 0.05 parts by weight of Zn, 0.04 to 0.08 parts by weightof Ga, 0.02 to 0.05 parts by weight of Sr, 0.002 to 0.01 parts by weightof Cd, and 0.003 to 0.005 parts by weight of Pb.

In addition, the finely ground metal powder may be ground repeatedlyuntil the particle size of the powder falls within a range of 1 to 2 μm.

In step (c), at least one liquid composition selected from the groupconsisting of sodium tetraborate (Na₂B₄O₇.10H₂O), sodium hydroxide(NaOH), sodium silicate (Na₂SiO₃), and hydrogen peroxide (H₂O₂) is mixedwith the finely ground oxide powder and the finely ground metal powderprepared in step (a) and step (b) to prepare a desulfurization catalyst.

In this step, the sodium tetraborate (Na₂B₄O₇·10H₂O) may be contained inan amount of 20 to 130 parts by weight, the sodium hydroxide (NaOH) maybe contained in an amount of 15 to 120 parts by weight, the sodiumsilicate (Na₂SiO₃) may be contained in an amount of 50 to 250 parts byweight, and the hydrogen peroxide (H₂O₂) may be contained in an amountof 10 to 50 parts by weight.

In addition, in this step, when mixing and reacting the mixed and finelyground oxide and metal powders prepared in steps (a) and (b), the oxidepowder and the liquid composition act as a chelating agent so that ametal chelate compound can be formed.

In addition, the pretreatment desulfurization agent formed in this stepis stabilized by sedimentation for 24 to 72 hours, and the sedimentedpretreatment desulfurization agent is separated and dried naturally tobe used as a powder catalyst for desulfurization. The liquid compositionremaining after the sedimented desulfurization catalyst is separated maybe used as a liquid catalyst for desulfurization.

In addition, in the desulfurization method using the pretreatmentdesulfurization agent according to the present invention, thedesulfurization function may be activated when it is mixed and combustedwith a combustible material.

A conventional desulfurization method removes sulfur oxides (SO_(x))from flue gas generated during combustion of a combustible material. Theconventional method requires a desulfurization facility for performingthe desulfurization process and incurs manpower and cost for operatingthe desulfurization facility. However, since the desulfurization methodof the present invention burns the pretreatment desulfurization agentalong with the combustible material, the pretreatment desulfurizationagent removes sulfur oxides through adsorption during the combustion,thereby reducing the content of sulfur oxides in flue gas. In this way,the method of the present invention exhibits a desulfurization effect.

In addition, the combustible material to which the pretreatmentdesulfurization agent according to the present invention can be appliedmay be a combustible material that generates heat through combustion.Examples of the combustible material include coal, petroleum, waste, andbiogas.

In addition, as described above, the pretreatment desulfurization agentis separated into a powder catalyst for desulfurization and a liquidcatalyst for desulfurization. Each of the powder catalyst and the liquidcatalyst is used alone or in combination with the other, depending onthe contents of C, H, N, and S of the combustible material. Therefore,the pretreatment desulfurization agent of the present invention canexhibit an excellent desulfurization effect in a simple and easy way ofuse.

Hereinafter, the configuration of a pretreatment desulfurization systemaccording to one embodiment of the present invention, which is to beapplied to a marine engine, will be described in detail with referenceto FIG. 1 .

The pretreatment desulfurization system according to the presentinvention is connected to a fuel supply line 30 of a marine engine 70 tosupply the pretreatment desulfurization agent (liquid catalyst fordesulfurization) in a certain mixing ratio with respect to fuel.

Usually, as the fuel of the marine engine 70, marine fuel oil, forexample, heavy oil such as bunker-A oil, bunker-B oil, or bunker-C oil,or light oil such as MGO, MDO, or DDO is used. Among them, bunker C oilis a high sulfur oil and generates a large amount of sulfur oxidesduring combustion thereof. Therefore, the use of bunker-C oil isregulated due to air pollution.

In FIG. 1 , reference numerals 10, 20, 30, 40, 50, and 60 denote a fueltank, a fuel supply pump, a fuel supply line, a fuel filter, aninjection pump, and an injection nozzle, respectively. A detaileddescription of the components will be omitted.

To this end, the pretreatment desulfurization system according to thepresent invention is equipped with a desulfurization agent tank 110having a predetermined volume for storing the pretreatmentdesulfurization agent, and one end of the desulfurization agent tank 110is connected to a metering pump 130 for quantitatively supplying thepretreatment desulfurization agent.

In addition, a flow meter 120 for checking the input flow rate of thepretreatment desulfurization agent, a check valve 140 for adjusting theinput flow rate, and a pressure gauge 150 are installed on the fuelsupply line 30 between the metering pump 130 and the marine engine 70.Therefore, it is possible to continuously check the fuel supply amountto the marine engine 70 and regulate the supply of the pretreatmentdesulfurization agent so that the pretreatment desulfurization agent issupplied in a predetermined ratio with respect to the fuel supplyamount.

The pretreatment desulfurization agent is preferably supplied and mixedin an amount of 0.1% to 10% by weight relative to 100% by weight of themarine fuel oil.

Referring to FIG. 2 , the pretreatment desulfurization agent isconnected to a line mixer 160 provided on the fuel supply line 30 forsupplying the marine fuel oil, and the pretreatment desulfurizationagent injected from one side and the marine fuel oil are sufficientlymixed in the line mixer 160 (this process is called line mixing). Thesufficiently mixed fluid mixture of the marine fuel oil and thepretreatment desulfurization agent is supplied to the marine engine.

Thereafter, the fluid mixture is combusted in the marine engine.Therefore, sulfur oxides generated during a combustion process areadsorbed and removed by the pretreatment desulfurization agent beforebeing discharged to the outside.

Through this process, even when high-sulfur marine fuel oil such asbunker-C oil is used as fuel, since sulfur oxides are almost perfectlyremoved during the combustion, it is possible to solve the air pollutionproblem caused by sulfur oxides.

Hereinafter, the present invention will be described in more detail withreference to Examples and Test Examples.

Examples and Test Examples presented herein are only for illustrativepurposes and are not intended to limit the scope of the presentinvention.

<Example> Preparation of Pretreatment Desulfurization Agent

As oxides, SiO₂ 150 kg, Al₂O₃ 150 kg, Fe₂O₃ 100 kg, TiO₂ 50 kg, MgO 200kg, MnO 100 kg, CaO 200 kg, Na₂O 150 kg, K₂O 200 kg, and P₂O₃ 50 kg weremixed and finely ground to form fine oxide powder.

As metals, Li 35 g, Cr 50 g, Co 10 g, Ni 60 g, Cu 180 g, Zn 350 g, Ga400 g, Sr 200 g, Cd 20 g, and Pb 30 g were mixed and finely ground toform fine metal powder.

The fine oxide powder and the fine metal powder are repeatedly ground tohave a particle size of 1 to 2 μm.

3000 kg of water was put into a reactor, the water was maintained at atemperature of 50° C. to 60° C., and 50 kg of sodium tetraborate(Na₂B₄O₇·10H₂O) were added thereto. After stirring for 30 minutes, 100kg of sodium hydroxide (NaOH) was added and stirred. Next, after 10minutes, the fine oxide powder was added in units of 100 kg at intervalsof 5 minutes and stirred for 2 hours or more. While stirring, thetemperature was raised to 60° C. to 80° C., and 100 kg of sodiumsilicate (Na₂SiO₃) was added. After stirring for 30 minutes, the finemetal powder was added in units of 20 g at intervals of 3 minutes andstirred. After stirring for 1 hour, 30 kg of hydrogen peroxide (H₂O₂)was added, stirred for another 30 minutes, and then naturally cooled for1 hour.

After cooling and stabilizing for 48 hours, the liquid composition andthe sedimented powder composition are separated from each other.

The sedimented powder composition was dried naturally and named as apowder catalyst for desulfurization (GTS-P).

In addition, the liquid composition remaining after the sedimentedpowder composition was removed was moved to a separate container andnamed as a liquid catalyst for desulfurization (GTS-W).

<Experimental Example 1> Test for Checking Reduction in Sulfur Oxide inMarine Engine Exhaust Gas

(1) Test Condition

In order to evaluate the desulfurization efficiency of the pretreatmentdesulfurization agent (liquid catalyst for desulfurization) prepared asdescribed above, 3.5% and 6.0% by weight of the pretreatmentdesulfurization agent was supplied to a fuel supply line connected to amarine engine so as to be mixed with 100% by weight of fuel, and themixture was burned. Next, a sulfur oxide reduction performance test wasconducted to analyze and compare the concentration of sulfur oxides inexhaust gas.

The specifications of the marine engine used for the test are shown inTable 1 below.

TABLE 1 Specifications of engine for test Maker Yanmar Model 4LOD Horsepower (Hp) 200 Number of Cylinders 4 in-line Combustion system Directinjection Aspiration Natural aspirated Dimensions (L × W × H, mm) 500 ×1550 × 1400 Cooling system Direct water cooling Marine gear MechanicalFuel consumption rate 100 mL/min

Fuel used: Bunker-C oil

Operating conditions: no-load operation

Supply amount and method of pretreatment desulfurization agent: 3.5% and6.0% by weight of the pretreatment desulfurization agent was mixed andsupplied to the fuel supply line with a metering pump with respect tothe fuel flow rate.

Exhaust gas analysis equipment: Germany VarioPlus Ind. MRU EmissionMonitoring System

Exhaust gas analysis method: exhaust gas was sampled from an exhaustpipe connected to the engine and with an analysis equipment (standardoxygen concentration of 17%)

Since the oxygen concentration in the exhaust gas was maintained at 17%to 18% in the engine no-load operation condition, the reference oxygenconcentration was set to 17% to prevent an excessive difference betweenthe measured concentration and the corrected concentration that is basedon the reference oxygen concentration.

(2) Test Method and Procedures

1) Main engine operation state and normal state

2) Preheat exhaust gas analysis system and perform zero setting

3) Perform measurement in a condition in which no pretreatmentdesulfurization agent was injected (30 minutes)

4) Perform measurement in a condition in which 6.0% by weight ofpretreatment desulfurization agent was injected (1 hour)

5) Repeat step 3) and step 4) one more time

6) Perform measurement in a condition in which no pretreatmentdesulfurization agent was injected (30 minutes)

7) Perform measurement in a condition in which 3.5% by weight ofpretreatment desulfurization agent was injected (1 hour)

8) Perform measurement in a condition in which no pretreatmentdesulfurization agent was injected (30 minutes)

9) Perform measurement in a condition in which 6.0% by weight ofpretreatment desulfurization agent was injected (1 hour)

10) Save data and stop analysis

TABLE 2 Test Condition Time Test condition 11:21-11:54 Fuel oil11:54-13:20 Pretreatment desulfurization agent 6.0% by weight13:20-14:03 Fuel oil 14:03-15:06 Pretreatment desulfurization agent 6.0%by weight 15:06-15:46 Fuel oil 15:46-16:46 Pretreatment desulfurizationagent 3.5% by weight 16:46-17:23 Fuel oil 17:23-18:25 Pretreatmentdesulfurization agent 6.0% by weight

(3) Result of Analysis of Sulfur Oxide (SO₂) Concentration (in Terms of17% Reference Oxygen Concentration)

FIG. 3 shows the analysis results of sulfur oxide (SO₂) concentrationfor the entire session of Experimental Example 1 performed according tothe test conditions, methods, and procedures described above, and Table3 summarizes data of the values of SO₂ concentration in each measurementsession of FIG. 3 . (in terms of 17% of reference oxygen concentration)

TABLE 3 SO₂ concentration for each measurement session (in terms of 17%of reference oxygen concentration) Measurement SO₂ concentration timeTest condition (ppm) Note 11:35-12:00 Fuel oil 102.00 Average value12:23-13:00 Pretreatment 0.01 Average desulfurization agent value 6.0%by weight 14:08 Fuel oil 100.0 Peak value 14:26-15:15 Pretreatment 0.00Average desulfurization agent value 6.0% by weight 15:51 Fuel oil 95.2Peak value 16:22-16:52 Pretreatment 29.19 Average desulfurization agentvalue 3.5% by weight 17:28 Fuel oil 94.5 Peak value 17:50-18:25Pretreatment 0.00 Average desulfurization agent value 6.0% by weight

Referring to FIG. 3 and Table 3, after 6.0% by weight and 3.5% by weightof the pretreatment desulfurization agent relative to 100% by weight ofthe fuel oil were sequentially injected into the fuel supply line, theconcentration of SO₂ was measured for each case. That is, the test wasperformed with four measurement sessions.

In a first measurement session, when only fuel oil was burned(measurement time: 11:35-12:00), the concentration of SO₂ in the exhaustgas was 102.00 ppm, but when 6.0% by weight of the pretreatmentdesulfurization agent was input (measurement time: 12:23-13:00), theconcentration of SO₂ rapidly dropped to 0.01 ppm.

In a second measurement session, when only fuel oil was burned(measurement time: 14:08), the concentration of SO₂ in the exhaust gaswas 100.00 ppm, but when 6.0% by weight of the pretreatmentdesulfurization agent was added relative to 100% by weight of fuel oil(measurement time: 4:26-15:15), the concentration of SO₂ rapidly droppedto 0.00 ppm.

In a third measurement session, when only fuel oil was burned(measurement time 15:51), the concentration of SO₂ in the exhaust gaswas 95.2 ppm, but when 3.5% by weight of the pretreatmentdesulfurization agent was added relative to 100% by weight of fuel oil(measurement time 16:22-16:52), the concentration of SO₂ rapidly droppedto 29.19 ppm.

In a fourth measurement session, when only fuel oil was burned(measurement time 17:28), the concentration of SO₂ in the exhaust gaswas 94.5 ppm, but when 6.0% by weight of the pretreatmentdesulfurization agent was added relative to 100% by weight of fuel oil(measurement time 17:50-18:25), the concentration of SO₂ rapidly droppedto 0.00 ppm.

The measurement results showed that the effect of reducing the SO₂emissions was improved when the mixing ratio of the pretreatmentdesulfurization agent was increased from 3.5% by weight to 6.0% byweight.

<Experimental Example 2> Test for Checking Reduction in Sulfur Oxide inMarine Engine Exhaust Gas

(1) Test Condition

The same as in Test Example 1

(2) Test Method and Procedures

The same as in Test Example 1

TABLE 4 Test Condition Time Test condition 09:06-09:44 Fuel oil09:44-10:54 Pretreatment desulfurization agent 3.5% by weight10:54-11:10 Fuel oil 11:10-11:37 Engine stop 11:37-13:02 Fuel oil12:02-13:08 Pretreatment desulfurization agent 6.0% by weight

(3) Result of Analysis of Sulfur Oxide (SO₂) Concentration (in Terms of17% Reference Oxygen Concentration)

FIG. 4 shows the analysis results of the sulfur oxide (SO₂)concentration for the entire session of Experimental Example 2 performedaccording to the test conditions, methods, and procedures describedabove, and Table 5 is a table in which data values of the concentrationof SO₂ in each measurement session of FIG. 4 are summarized. (In tams ofa reference oxygen concentration of 17%)

TABLE 5 SO₂ concentration for each measurement session (in terms of thereference oxygen concentration of 17%) Measurement SO₂ concentrationtime Test condition (ppm) Note 09:12-09:40 Fuel oil 96.43 Average value10:18-10:51 Pretreatment 29.54 Average desulfurization agent value 3.5%by weight 11:55-12:44 Fuel oil 98.93 Average value 12:57-13:06Pretreatment 0.00 Average desulfurization agent value 6.0% by weight

Referring to FIG. 4 and Table 5, after 6.0% by weight and 3.5% by weightof the pretreatment desulfurization agent relative to 100% by weight ofthe fuel oil were injected into the fuel supply line, the concentrationof SO₂ was measured for each case. That is, the test was performed withtwo measurement sessions.

In a first measurement session, when only fuel oil was burned(measurement time: 09:12-09:40), the concentration of SO₂ in the exhaustgas was 96.43 ppm, but when 3.5% by weight of the pretreatmentdesulfurization agent was input with respect to 100% by weight of oil(measurement time: 10:18-10:51), the concentration of SO₂ rapidlydropped to 29.54 ppm.

In a second measurement session, when only fuel oil was burned(measurement time: 11:55-12:44), the concentration of SO₂ in the exhaustgas was 98.93 ppm, but when 6.0% by weight of the pretreatmentdesulfurization agent was input with respect to 100% by weight of oil(measurement time: 12:57-13:06), the concentration of SO₂ rapidlydropped to 0.00 ppm.

The measurement results showed that the effect of reducing the SO₂emissions was improved when the mixing ratio of the pretreatmentdesulfurization agent was increased from 3.5% by weight to 6.0% byweight.

As can be seen from the results of Test Examples 1 and 2, when fuel andthe pretreatment desulfurization agent were burned together, the SO₂concentration in the exhaust gas was reduced by at least 69% and by 100%at a maximum compared to the case where only fuel is burned. Inaddition, when the pretreatment desulfurization agent was increased from3.5% by weight to 6.0% by weight, the reduction in the SO₂ emissions wasincreased.

INDUSTRIAL APPLICABILITY

The present invention can be widely used in pretreatment desulfurizationsystems.

1. A marine fuel oil pretreatment desulfurization system using apretreatment desulfurization agent, the system comprising: adesulfurization agent storage tank configured to store a liquid-phasepretreatment desulfurization agent; and a metering pump for supplyingthe desulfurization agent from the desulfurization agent storage tank toa fuel supply line through which marine fuel oil is supplied to a marineengine, in a predetermined ratio, wherein the marine fuel oil and thepretreatment desulfurization agent are mixed and the resulting mixtureis supplied to the marine engine so that sulfur oxides are adsorbed andremoved during combustion of the fluid mixture.
 2. The system accordingto claim 1, wherein the pretreatment desulfurization agent comprises:(a) at least one oxide selected from the group consisting of SiO₂,Al₂O₃, Fe₂O₃, TiO₂, MgO, MnO, CaO, Na₂O, K₂O, and P₂O₃; (b) at least onemetal selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga,Sr, Cd, and Pb; and (c) at least one liquid composition selected fromthe group consisting of sodium tetraborate (Na₂B₄O₇·10H₂O), sodiumhydroxide (NaOH), sodium silicate (Na₂SiO₃), and hydrogen peroxide(H₂O₂).
 3. The system according to claim 2, wherein the oxide comprises15 to 90 parts by weight of SiO₂, 15 to 100 parts by weight of Al₂O₃, 10to 50 parts by weight of Fe₂O₃, 5 to 15 parts by weight of TiO₂, 20 to150 parts by weight of MgO, 10 to 20 parts by weight of MnO, and 20 to200 parts by weight of CaO, 15 to 45 parts by weight of Na₂O, 20 to 50parts by weight of K₂O, and 5 to 20 parts by weight of P₂O₃, and themetal comprises 0.0035 to 0.009 parts by weight of Li, 0.005 to 0.01parts by weight of Cr, 0.001 to 0.005 parts by weight of Co, 0.006 to0.015 parts by weight of Ni, 0.018 to 0.03 parts by weight of Cu, 0.035to 0.05 parts by weight of Zn, 0.04 to 0.08 parts by weight of Ga, 0.02to 0.05 parts by weight of Sr, 0.002 to 0.01 parts by weight of Cd, and0.003 to 0.005 parts by weight of Pb.
 4. The system according to claim2, wherein the oxide and metal have a particle size of 1 to 2 μm and aspecific gravity of 2.5 to 3.0.
 5. The system according to claim 2,wherein the sodium tetraborate (Na₂B₄O₇·10H₂O) is contained in an amountof 20 to 130 parts by weight, the sodium hydroxide (NaOH) is containedin an amount of 15 to 120 parts by weight, the sodium silicate (Na₂SiO₃)is contained in an amount of 50 to 250 parts by weight, and hydrogenperoxide (H₂O₂) is contained in an amount of 10 to 50 parts by weight.6. The system according to claim 2, wherein the pretreatmentdesulfurization agent is configured such that the oxide, the metal, andthe liquid composition form a metal chelate compound.
 7. The systemaccording to claim 2, wherein the pretreatment desulfurization agent hasa sulfur oxide (SO_(X)) adsorption effect that is activated attemperatures in a range of 400° C. to 1200° C.
 8. The system accordingto claim 1, wherein the pretreatment desulfurization agent is mixed in aratio of 0.1 to 10 parts by weight with respect to 100 parts by weightof the marine fuel oil.
 9. The system according to claim 1, wherein thepretreatment desulfurization agent is mixed in a ratio of 6 parts byweight with respect to 100 parts by weight of the marine fuel oil. 10.The system according to claim 1, wherein the fuel supply line isequipped with a line mixer, and the metering pump introduces thepretreatment desulfurization agent into the marine fuel oil in a statein which the metering pump is connected to the line mixer.
 11. Thesystem according to claim 10, further comprising a flow meter, a checkvalve, and a pressure gauge which are disposed between the line mixerand the metering pump.
 12. The system according to claim 1, wherein themarine fuel oil is any heavy oil among heavy oils including bunker-Aoil, bunker-B oil, and bunker-C oil, or any light oil among light oilsincluding MGO, MDO, and DDO.